Mc Cable Support Above Ceiling

Type mc cable can be unsupported where the cable is.

Mc cable support above ceiling.

The two main reasons for this are electrical safety and fire safety. So we had a discussion at work today regarding support of 3 8 mc above a drop ceiling. This new 2017 code language also allows the electrician to install mc cable on the underside of floor and ceiling joists assuming the electrician supports the cable at every provided joist. We were using metal tie wire that comes in bundles but we stopped when questioned by the gc.

Various reasons are given for this practice such as. 1 fished through concealed spaces in finished buildings or structures where support is impracticable or 2 not more than 6 ft long from the last point of cable support to the point of connection to luminaires or other electrical equipment within an accessible ceiling. Section 330 30 requires mc cable to be fastened within 12 inches of each box and at 6 foot intervals. This is also new for 2017 as permission for this method of installation did not exist prior to the 2017 code cycle.

Section 358 30 requires emt to be fastened within 3 feet of each box and at 10 foot intervals. Are cable ties or ty raps allowed for supporting type mc cable in a ceiling. My co worker and i both understand that you cannot support mc with batwings to the ceiling grid wire. He said however that you can support it on the support wire holding the light fixtures up since it s part of the electrical system and not part of the grid.

Section 348 30 requires fmc to be fastened within 12 inches of each box and at 4 5 foot intervals. Section 330 30 a provides the general requirements and permits cable ties. General consensus is that you shouldn t support mc cable from suspended ceiling wires yet i d venture a guess anyone of us who said we ve never done that might be lying but i can t find it. It has long been accepted as good practice to support cables above suspended ceilings.

However you may have seen cables slung over suspended ceilings in a haphazard fashion and resting on the ceiling grid. Mc supports and suspended ceiling wires forgive me if this has already been addressed i searched for about 15 minutes and couldn t find a previous topic. The ceiling support system shall be permitted to support branch circuit wiring and associated equipment where installed in accordance with the ceiling system manufacturer s instructions.